ᐅ Is window planning strictly required to follow DIN 5034-2021-08?

Our architect says that the window size must be planned according to DIN 5034-2021-08 (new single-family house). This is estimated to cost about 3000 EUR, as complex calculations and outsourcing are necessary. How binding is this DIN standard? Would the building permit / planning permission likely still be approved if the brightness (etc.) required by the standard is not fully met everywhere?

tom_tom schrieb:

Would the building permit / planning permission probably still be granted if the brightness (etc.) specified in the standard is not met everywhere?

There is no mention of that in the building permit / planning permission application. As far as I know, the DIN standard is not a legal requirement but a guideline that architects use for reference. However, I have never seen it applied in single-family houses. So no, the approval of the building permit / planning permission does not depend on that and it is not checked there.

An architect who wants to charge $3,000 for that in a single-family house, I would send packing. Especially since every "standard" single-family house does not cause any issues anyway.

Thank you. This approximate amount is probably the standard fee charged by companies contracted to calculate it accurately. The architect says he cannot do it himself. The simplified standard seems to have been discontinued.

I am curious about the legal basis for the calculation according to the DIN standard.
There are many recommendations included, such as 10% of the floor area as window area. However, I am not aware that these are mandatory (unless this has changed recently). Therefore, my question is where the legal basis for this can be found.
Furthermore, I would like to know why the architect does not refer to the more recent DIN EN 17037, which actually replaces the old DIN standard.

Finally, a note that the only exclusive legal obligation is found in the state building code. In Bavaria, see Article 45. There are no additional legal requirements. The DIN standard can be applied voluntarily to improve comfort. Please do not trust the 3k calculation.

Thank you for your information. I will ask him about the basis for this. Maybe someone else knows something about it as well.

tom_tom schrieb:

Maybe someone else knows something about this.

I’m interested as well. I’m only familiar with such assessments in commercial buildings (mainly office buildings), where lighting is a matter of occupational health and safety and therefore mandatory.